1(function trackUserJourney() {
2    const TRACKED_PARAMS = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content', 'gclid', 'fbclid'];
3    const searchParams = new URLSearchParams(window.location.search);
4    let currentParams = {};
5    
6    // 1. Assign a persistent Visitor ID
7    let visitorId = localStorage.getItem("visitor_id");
8    if (!visitorId) {
9      visitorId = 'vid_' + Date.now() + '_' + Math.random().toString(36).substr(2, 9);
10      localStorage.setItem("visitor_id", visitorId);
11    }
12    
13    // 2. Extract URL Parameters
14    let hasParams = false;
15    for (const key of TRACKED_PARAMS) {
16        if (searchParams.has(key)) {
17            currentParams[key] = searchParams.get(key);
18            hasParams = true;
19        }
20    }
21    
22    if (hasParams) {
23        const timestamp = new Date().toISOString();
24 
25        // 3. First Touch (Never Overwrite)
26        if (!localStorage.getItem("initial_source")) {
27            localStorage.setItem("initial_source", JSON.stringify({ ...currentParams, first_visit: timestamp }));
28        }
29 
30        // 4. Last Touch (Always Overwrite)
31        sessionStorage.setItem("session_source", JSON.stringify({ ...currentParams, session_start: timestamp }));
32        
33        // 5. Multi-Touch Journey Array
34        try {
35          const stored = localStorage.getItem("touchpoints");
36          const touchpoints = stored ? JSON.parse(stored) : [];
37          const last = touchpoints[touchpoints.length - 1];
38          
39          // Prevent rapid duplication from page refreshes
40          if (!last || last.source !== currentParams.utm_source || last.campaign !== currentParams.utm_campaign) {
41            touchpoints.push({
42              source: currentParams.utm_source,
43              medium: currentParams.utm_medium,
44              campaign: currentParams.utm_campaign,
45              timestamp: timestamp
46            });
47            localStorage.setItem("touchpoints", JSON.stringify(touchpoints));
48          }
49        } catch(e) {}
50    }
51})();